Reasons for the Expansion and contraction of Persian Seljuk domination in Bahrain

After the Mongol invasion, the islands of the Persian Gulf became more important. One of these islands was Bahrain, which was considered as one of the important economic and commercial centers by powerful countries. Atabak Abu Bakr Salghari (623-658) AH, was able to invade and capture Bahrain, after capturing the Kish Island. using the weakness of the Oyuni government of Bahrain (469-636) AH.In the end, the Salgharian left Bahrain under the force of the tribes of BaniAmer and Mahmud Qalahati (641-676) AH and the threats of the Mongols. then the tribe of BaniAmer (654 AH) became the rulers of this land. This article intends to describe the conquest of Bahrain by the Salgharian using library sources and descriptive-analytical research methods and explains the reasons for their retreat.Studies show that different reasons, at different levels, have led to the departure of the Salgaryan from Bahrain. At the local level: reasons such as the BaniAmercompetition,At the regional level: the emergence of the king of Hormuz,And finally, at the international level: the insecurity of Iran after the Mongol invasions.